The present invention relates to a printed board for face mounting and, more particularly, to an improvement in a double-sided printed board.
A typical conventional printed board which incorporates a V.sub.SS plate (power supply plate) is formed using a multi-layer board, and the V.sub.SS plate is provided in its inner layer.
The following is one example of a structure of a multi-layer board, e.g., a four-layer structure, having the V.sub.SS plate in its inner layer.
Namely, obverse surface wirings are provided on the obverse surface of the board, while reverse surface wirings are provided on its reverse surface. Through-holes are provided in the board, and conductors are disposed inside the through-holes to provide electrical communication between the obverse and reverse surface wirings. Further, a double-layer V.sub.SS plate (power supply layer) consisting of first and second V.sub.SS plate layers is provided inside the board so that the power supply layer extends perpendicularly to the through-hole conductors.
In general, the above-described multi-layer board is produced by stacking a necessary number of resin sheets each having a pattern formed thereon, heating them under pressure to harden the resin, providing holes (through-holes) at necessary positions with a drill, and disposing conductors inside the holes to thereby make the patterns conductive to each other.
It should be noted that the printed board is described, for example, in the "Electronic Materials", Kogyo Chosakai Publishing Co., Ltd., Tokyo, for October, 1983, pp. 15-164, for October, 1984, pp. 15-128, and for April, 1984, pp. 143-148.